scholarly journals The Formation Mechanism of Surface Landslide Disasters in the Mining Area under Different Slope Angles

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Chi Mu ◽  
Xueyi Yu ◽  
Bingchao Zhao ◽  
Dongdong Zhang ◽  
Xuwei Mao ◽  
...  
Keyword(s):  
Stability Analysis ◽  
Formation Mechanism ◽  
Slope Angle ◽  
Mining Area ◽  
Rock Stratum ◽  
Effective Prevention ◽  
Surface Movement ◽  
Working Face ◽  
Geological Conditions ◽  
Movement And Deformation

Slope stability analysis is important for the safe mining of mineral resources. The collapse of goafs in loess gullies can lead to natural disasters such as surface landslides. In this context, this study analyzes monitoring data obtained from surface observation in the Shendong mining area of the Hanjiawan coal mine based on the geological conditions therein. The monitoring results show that the working face experiences a starting period, an active period, and a declining period, from the start of mining to the end of the working face. At the initial mining stage, there is no evident surface movement or deformation in the mining area. When the advance distance of the 12106 working face is between 13 m and 109 m, the surface movement and deformation vary significantly, and the maximum subsidence reaches 1963 mm, which is enough to cause landslides. We select the physical and mechanical parameters of the rock and soil in the mine and then simulate the formation mechanism of surface landslides under different slope angles of the mining area using FLAC3D software. Because of the collapse of the mined-out area, the overlying strata structure is destroyed, the subsidence basin is shifted to the center as a whole, and the slope mass is subjected to tensile and compression deformation, resulting in plastic damage, which develops downward along the crack and leads to a collapse because of the discontinuous movement and deformation of the surface; moreover, step-type ground fissures are produced. The results also show that when the slope angle is greater than 60°, the displacement of the slope mass is not uniform, and the rock stratum in a position with large displacement loses its support, leading to landslides; when the slope angle is less than 30°, the bedrock surface forms a sliding surface and develops to the surface, thus decreasing the possibility of landslides. Based on the stability analysis of the collapsed slope in the goaf of the loess gully, a scientific basis is provided for the effective prevention and control of geological disasters in the Shendong mining area.

scholarly journals Rebound Mechanism and Control of the Hard Main Roof in the Deep Mining Roadway in Huainan Mining Area

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Denghong Chen ◽  
Chao Li ◽  
Xinzhu Hua ◽  
Xiaoyu Lu ◽  
Yongqiang Yuan ◽  
...  
Keyword(s):  
Slope Angle ◽  
Bending Moment ◽  
Main Roof ◽  
Mining Area ◽  
Calculation Model ◽  
Surrounding Rock ◽  
Tensile Failure ◽  
Damage Area ◽  
Critical Range ◽  
Working Face

Taking the occurrence conditions of the hard main roof in the deep 13-1 coal mining roadway in Huainan mining area as the research object, based on the mechanical parameters of the surrounding rock and the stress state of the main roof obtained by numerical simulation, a simply supported beam calculation model was established based on the damage factor D, main roof support reaction RA, RB, and critical range C (9 m) and B (7 m) at the elastoplastic junction of the solid coal side and mining face side (hereinafter referred to as “junction”). Considering that the damage area still has a large bearing capacity, the vertical stress of the main roof at the junction is K1γH (0.05γh, 0.15γh, and 0.25γh) and K2γH (0.01γh, 0.10γh, and 0.2γh). The maximum deflection is 21 mm, 324 mm, and 627.6 mm, respectively. According to the criterion of tensile failure, the maximum bending moment of the top beam is 209 mN·m at the side of the working face 3.1 m away from the roadway side when K1 = 0.15 and K2 = 0.10, and the whole hard main roof is in tensile failure except the junction. To control the stability of the top beam and simplify the supporting reaction to limit the deformation of the slope angle, RC and RD are used to construct the statically indeterminate beam. By adding an anchor cable and advance self-moving support to the roadway side angle, the problem of difficult control of the surrounding rock with a large deformation of the side angle roof is solved, which provides a reference for roof control under similar conditions.

Study on the Regularity of Surface Movement and Deformation in Long Coal Face with Large Mining Height

2012 ◽  
Vol 594-597 ◽  
pp. 86-91
Author(s):  
Zu Qiang Xiong ◽  
Jun He ◽  
Lei Lei Zhao
Keyword(s):  
Horizontal Displacement ◽  
Mining Area ◽  
Coal Seams ◽  
Coal Face ◽  
Abscission Layer ◽  
Surface Movement ◽  
Face Length ◽  
Large Mining Height ◽  
Movement And Deformation ◽  
Space Range

It is an important way to realize mine intensive production by increasing of the coal face length. During the transformation period of mining methods about thick coal seams, the character parameters of surface movement and deformation will be provided to guarantee scientifically mining of thick coal seams in Jincheng mining area. In this paper, numerical simulation, theoretical analysis and field measurement are used for studying the influence of coal face length on surface movement and deformation in the condition of large height mining. The results show that the separated strata space range extended with the increasing of coal face length and advancing distance, the surface movement and deformation become more violent, the mining influenced range also gradually expands, and the maximum surface subsidence and horizontal displacement increases gradually in form of linear relationship. In the condition of fast mining, the duration of abscission layer reduces, and the surface movement and deformation shows obviously hysteretic and zonal characteristic.

Analysis on Characteristics of Surface Subsidence with Han Jia Wan Coal Mine

2012 ◽  
Vol 524-527 ◽  
pp. 520-524 ◽  
Author(s):  
Xue Yi Yu ◽  
Peng Wang ◽  
Xing Liang Li
Keyword(s):  
Coal Mine ◽  
Scientific Basis ◽  
Surface Subsidence ◽  
Surface Cracks ◽  
Surface Movement ◽  
Working Face ◽  
Shallow Coal Seam ◽  
Movement And Deformation ◽  
Main Factors ◽  
Movement Parameters

Surface subsidence has some peculiarities for the mining of the Han jia wan coal mine. Based on the surface movement observation of 2304 working face in Han jia wan coal mine, mining strata movement parameters are analyzed, the main factors which influence the formation of surface cracks in the gob are proposed and the failure mechanism of surface movement and deformation are studied for the mining of shallow coal seam and thick loose bed. Correlative parameters are presented and scientific basis is established for the coal mining under buildings, rail and water and the leaving of the safety pillar in the future.

scholarly journals Disastrous Mechanism of Water Discharge in Abandoned Gob above the Stope in Mining Extra-Thick Coal Seam

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Haixiao Lin ◽  
Feng Yang ◽  
Zhengzheng Cao ◽  
Yue Wang ◽  
Xiaojian Jiao
Keyword(s):  
Coal Seam ◽  
Water Discharge ◽  
Mining Area ◽  
Thick Coal Seam ◽  
Research Results ◽  
Key Stratum ◽  
Working Face ◽  
Geological Conditions ◽  
Induced Fractures ◽  
Seam Mining

The Datong mining area is a typical double system coal seam mining area in China, where the Jurassic and Carboniferous coal seams are mined simultaneously. The upper Jurassic coal seam has been largely mined, leaving a large amount of gob area. Besides, a large amount of harmful water is accumulated. With the exploitation of the 3-5# extra-thick coal seam in the Carboniferous system, the scope of overburden damage is greatly increasing, and the mining fracture field is further developed. Once the mining-induced fractures connect with the overlying gob, it is easy to induce the water discharge disaster. With the mining geological conditions of the 8202 working face in the Tongxin coal mine as references, the disastrous mechanism of water discharge in the abandoned gob above the stope in the mining extra-thick coal seam is researched by numerical simulation with the UDEC numerical software, and the research results are obtained. The water in the overlying gob percolates through the mining-induced fractures in the higher key layer forming a “shower” seepage pattern. The water in the above gob converges in the key fracture channel, flowing into the working face. The seepage in the fractures in the high key stratum experiences the process of increase, decrease, and stabilization, related with the stretching and extrusion deformation between the high key stratum blocks. Compared with other fractures, the flow rates in the No.2 and No.4 fractures in the far field key lay are larger, because the fractures are in the tension state, forming the “saddle-shaped” flow pattern. The influencing distance of mining-induced seepage is about 80 m in front of the working face. The research results provide a guided reference for the prediction and prevention of water discharge disaster in an abandoned gob above the stope in a mining extra-thick coal seam.

Research on the Simulation of the Roof Fracture about the Gob-Side Entry Retaining

2013 ◽  
Vol 734-737 ◽  
pp. 624-627 ◽  
Author(s):  
Jian Jun Shi ◽  
Run Hua Wu ◽  
Tao Yong ◽  
Jing Zhong Guo
Keyword(s):  
Main Roof ◽  
Rock Stratum ◽  
Effective Measure ◽  
Energy Group ◽  
Key Stratum ◽  
Working Face ◽  
Geological Conditions ◽  
Research Findings ◽  
The Stability ◽  
Basic Features

The geological conditions of haulage roadway of the working face 1528 in GeQuan Coal Mine, which belongs to the JiZhong Energy Group CO., Ltd., and the research findings of Key Stratum Theory was taken into consideration, based on which established a mechanical model could reflect the basic features of rock stratum and made a profound investigation on the form and conditions of the fractures on main roofs. A systematic study on the stress, deformation, and damage characters of fractures on main roofs beyond a retained entry has been made by the laboratory test. The experiment shows that the deeper the fracture is in the rib, the greater the differences between dimension of compression and deformation will likely be, and the greater the influences on the stability of surrounding rock will it has. At the same time, smaller is the overhanging beam in mined-out area, more beneficial to roadway maintenance. On a certain deformation of main roof, it creates subsidence that is great difference in different position of a roadway. The subsidence near those mined-out areas is much more than those near the ribs. The application of a strong and effective measure could help cut the roof out and assure its stability.

The Numerical Simulation of Overburden Strata Failure Law by Full-Mechanized Caving Mining in Extra Thick Coal Seams

2014 ◽  
Vol 962-965 ◽  
pp. 1179-1182 ◽  
Author(s):  
Shao Jie Feng ◽  
Xue Fang Zhao ◽  
Shi Guo Sun
Keyword(s):  
Numerical Simulation ◽  
Mining Area ◽  
Fracture Zones ◽  
Thick Coal Seam ◽  
Thick Seam ◽  
Fractured Zone ◽  
Working Face ◽  
Geological Conditions ◽  
Close Proximity ◽  
Superposition Effect

Given the irrationality and limitations in thick coal seam of the empirical formula of height of water flowing fractured zone , this article reveals the special thick seam fully mechanized mining damaging rules of overlying rock and determines the height of water flowing fractured zone with 3D finite element numerical simulation,according to the complex geological conditions and the special thick seam fully mechanized mining methods of Laohutai ore mining working face E5400 as an example. Results show that the destruction of repeated mining area of the overlying rock will have superposition effect and the superposition effect will increase with the development of mining; the fracture sharp of water fracture zones is in close proximity to the "arch". Simulation results and the actual detection height fitting is better, so it assesses the range of overburden water flowing fracture zones and rationality of the height.

Study on Surface Movement and Deformation Characteristics and Pillar Stability of Large Strip Mining under Deep Mining

2013 ◽  
Vol 734-737 ◽  
pp. 531-534
Author(s):  
Jun Tao Chen ◽  
Kai Kai Sheng ◽  
Li Min Yin ◽  
Chuan Qiang Wu
Keyword(s):  
Practical Significance ◽  
Strip Mining ◽  
Deformation Characteristics ◽  
Mining Technology ◽  
Pillar Stability ◽  
Deep Mining ◽  
Surface Movement ◽  
Working Face ◽  
Movement And Deformation ◽  
Overlying Strata

Large strip mining technology could effectively control the surface subsidence inducing from overlying strata movement and realize green mining. Bored stress and deformation sensors were laid in 4301 working face pillar of Shandong energy zibo mining group tangkou coal, analyzing the strip pillar stress pre and post working face; numerical simulation was used to study the influence of overlying strata from reserved size of strip pillar. According to the observation results of surface movement and deformation, law of surface movement and deformation characteristics was studied, which contributed to the practical application of large strip mining technology under deep mining and had the important theoretical and practical significance for mining under buildings ,railways and water in Chinese.

scholarly journals Ground Subsidence Evolution from 1000 m Deep Mining: A Case Study in Fengfeng Mining Area

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Yueguan Yan ◽  
Ming Li ◽  
Jibo Liu ◽  
Weitao Yan ◽  
Jinman Zhang ◽  
...  
Keyword(s):  
Eastern China ◽  
Mining Area ◽  
Ground Subsidence ◽  
Small Displacement ◽  
Deep Mining ◽  
Deep Mine ◽  
Surface Movement ◽  
Mining Depth ◽  
Movement And Deformation ◽  
Influence Radius

The mining of coal resources in eastern China has entered the stage of deep mining, and many mines have reached the depth of 1000 meters. Different from shallow and moderate depth mining, the temporal and spatial evolution regulation of surface movement and deformation under deep mining has its particularity. Combining with the geological and mining conditions of Fengfeng mining area, this paper systematically studies the characteristics of surface movement under the condition of shallow, moderate, and near kilometer mining depth. By means of field measurement, InSAR monitoring, we get the subsidence data under different mining depth and get the relevant subsidence parameters by inversion. Through comparative analysis, the special law of subsidence under the mining depth of 1000 meters is obtained. The results show that under the condition of nearly 1000 meters mining depth, the surface movement and deformation have the characteristics of large displacement angle, small displacement deformation value, and large main influence radius. The regulation of small proportion of active period of maximum subsidence point, gentle shape of surface movement basin, and low mining adequacy are obtained. The research results provide technical references for deep mining under buildings, railways, and water bodies and provide basis and reference for scientific mining and safe recovery of coal pillars in kilometer deep mine.

Stress Evolution and Deformation Control Technology for Deep Mining Influenced Roadway

2011 ◽  
Vol 90-93 ◽  
pp. 137-145
Author(s):  
Jia Guang Kan ◽  
Nong Zhang ◽  
Hai Wei Zhang ◽  
Zhi Yi Zhang ◽  
Guang Yao Si
Keyword(s):  
Coal Pillar ◽  
Surface Displacement ◽  
Mining Area ◽  
Surrounding Rock ◽  
Stress Evolution ◽  
Deformation Control ◽  
Working Face ◽  
Geological Conditions ◽  
Basic Ideas ◽  
Roadway Deformation

In order to effectively control deep roadway under mining influence, based on the typical engineering geological conditions of Dingji coalmine in Huainan mining area, we researched on the laws of stress evolution and failure mechanism of roadway influenced by working face advancing by using numerical simulation and applying field test. The results showed that the surrounding rock stress of roadway ribs increased gradually with face advancing, vertical stress peak transfer to in-depth of roadway surrounding rock, the trend of roadway surface displacement variation consistent with corresponding stress variation. An appropriate coal pillar size (105 m) was proposed. We put forward the basic ideas for surrounding rock controlling and surrounding rock reinforce technology, namely U-steel support back grouting and bolt-cable cooperative supporting. By roadway deformation, roof layer separation and borehole detecting, we found out that displacement of roadway ribs was less than 250 mm, subsidence of roof was less than 110 mm, and the roadway deformation has been effectively controlled.

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